1. Field of the Invention
The present invention pertains to the art of dishwashers and, more particularly, to a dishwasher including a system for adding a washing agent into a washing chamber by delivering washing fluid to a booster agent dispenser provided on an upper rack of the dishwasher during a select portion of an overall washing operation.
2. Description of the Related Art
In the art of dishwashers, it is known to provide multiple, vertically spaced spray arms within a single wash tub in order to enhance the spray patterns of washing fluid. For use with these various spray arm arrangements, many different types of fluid distribution systems have been developed to address different problems or to provide a dishwasher with specific functionality. For instance, in order to increase the distribution of washing fluid, it is known in the art to provide a dishwasher tub with a lower, rotatable spray arm mounted for rotation below a lower rack, an upper, rotatable spray arm mounted above an upper rack and an intermediate, rotatable spray arm provided below the upper rack. In such an arrangement, the intermediate spray arm is mounted to the upper rack for concurrent movement into and out of the tub of the dishwasher. To accommodate this movement, a fluid connection must be made to the intermediate spray arm upon retraction of the upper rack into the tub.
If the upper rack is vertically adjustable, additional provisions must be made to provide the necessary fluid connection when the upper rack is in each of the various vertical orientations. In general, this adjustability function is accomplished by fixedly mounting a valve and manifold assembly to the tub at the height of the upper rack, with the manifold including multiple ports which can be alternatively accessed to provide the requisite washing fluid flow to the intermediate spray arm.
As an additional consideration, it can be desirable to provide a flow control system to regulate the flow timing to each of the spray arms. For instance, based on water pressure or other reasons, it may not be feasible to provide flow to each of the spray arms simultaneously. If this is the case, separate and distinct fluid conduits and/or complicated valving may be employed in combination with a water diverter mechanism in order to selectively direct the washing fluid to the lower wash arm, the upper wash arm, the intermediate wash arm or certain combinations of the wash arms.
As a still further consideration, it can be desirable to enable the timed delivery of additional washing agent into a dishwashing chamber in connection with the regulated flow to the spray arms. In this regard, many attempts have been made in the art of dishwashers to provide improved detergent dispersion and effectiveness. One solution to the problem involves directing a cleaning agent from a dispenser directly into a spray arm. Examples of this type of dispenser are demonstrated by UK Patent Application No. GB 2321590 and U.S. Pat. No. 5,235,994. Another solution involves impinging washing fluid from a rotating spray arm directly into an exposed dispenser container to slowly dissolve and distribute a cleaning agent, as demonstrated by International Publication WO 2009/083576. It is also known in the art to provide an auxiliary dispenser for enhancing the performance of a dishwasher as taught by U.S. Pat. No. 7,475,696.
With all the above in mind, there is still seen to be a need in the art of dishwashers for an improved cleaning agent dispersal system for use in selectively supplementing the operation of a standard detergent dispenser in providing an optimal amount of detergent during distinct portions of an overall washing operation. More specifically, it is seen as beneficial to provide a dispenser that can be easily accessed by a user and selectively utilized to aide in the cleaning of kitchenware by quickly and effectively distributing a chemical agent within a dishwashing chamber, particularly during the distribution of washing fluid to one or more auxiliary spray units provided on an upper rack of a dishwasher.